1997 PCED OBDII-Diesel | SECTION 5C: Pinpoint Tests |
T1 DIAGNOSTIC TROUBLE CODE (DTC) P1663 — FDCS CIRCUIT FAILURE
- DTC 1663 indicated that the PCM has detected a failure on the FDCS line.
- Possible causes:
- Open/short in FDCS circuit
- Non-powered IDM
- IDM
- PCM
- Check for other codes.
- Key on, engine off.
- Perform KOEO On-Demand Self Test and retrieve Continuous DTCs
Was only DTC P1663 present?
| Yes | No |
|---|
| If DTC P1663 was present, GO to T2. | If DTCs P1667 and P1663 are set together, with or without DTC P1668, GO to U6. If DTC P1298 is also present, REPLACE the IDM. If DTC P1662 is also present, GO to W1. |
T2 CHECK VOLTAGE ON FDCS CIRCUIT 821 (BR/O)
- 1: Install breakout box, connect PCM to breakout box.
- 2: Key on, engine off.
- 3: Measure voltage on Circuit 821 (BR/O) between PCM Test Pins 95 and ground Pins 25, 51, 76, 77, 91 and 103.
Is voltage of 0.6 ± 0.1 volt present?
| Yes | No |
|---|
| GO to T3. | Voltage of less than 0.5 present, GO to T4. Above 4.0 volts is present, GO to T5. |
T3 PERFORM OUTPUT STATE CHECK
- Key on, engine off.
- Perform KOEO Output State Self Test. Toggle output by pressing and releasing the accelerator pedal.
- Measure voltage between PCM Test Pin 95 and ground Pins 25, 51, 76, 77, 91 and 103.
Did the output voltage toggle from 0.6 ± 0.1 volt to B+ volts?
| Yes | No |
|---|
| Intermittent failure. GO to T8. | REPLACE the PCM. RESTORE vehicle. CLEAR DTCs and RETEST. |
T4 CHECK FOR OPEN ON FDCS CIRCUIT 821 (BR/O)
- Key off.
- Disconnect the PCM from breakout box.
- Disconnect the IDM connector.
- Measure resistance on Circuit 821 (BR/O) between PCM Test Pin 95 and Pin 17 on the IDM harness connector.
Is resistance less than 5 ohms?
| Yes | No |
|---|
| GO to T6. | REPAIR open in Circuit 821 (BR/O). RESTORE vehicle. CLEAR DTCs and RETEST. |
T5 CHECK FDCS CIRCUIT 821 (BR/O) FOR SHORT TO POWER
- PCM disconnected.
- Key on, engine off.
- Measure voltage on Circuit 821 (BR/O) between PCM Test Pin 95 and ground Pins 25, 51, 76, 77, 91 and 103.
Is voltage present?
| Yes | No |
|---|
| REPAIR short to power on Circuit 821 (BR/O). | GO to T7. |
T6 CHECK FDCS CIRCUIT 821 (BR/O) FOR SHORT TO GROUND
- Key off.
- Measure resistance between PCM Test Pin 95 and ground Pins 25, 51, 76, 77, 91 and 103.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| GO to T7. | REPAIR short to ground on Circuit 821 (BR/O). RESTORE vehicle. CLEAR DTCs and RETEST. |
T7 CHECK PCM OUTPUT STATE FUNCTION
- Key off.
- Connect PCM to breakout box.
- IDM disconnected.
- Perform KOEO Output State Self Test.
- Measure voltage between PCM Test Pin 95 and ground Pins 25, 51, 76, 77, 91 and 103 while pressing and releasing accelerator pedal.
Did the output voltage toggle from 0.5 ± 0.1 volt to 0 volt?
| Yes | No |
|---|
| REPLACE the IDM. RESTORE vehicle. CLEAR DTCs and RETEST. | REPLACE the PCM. RESTORE vehicle. CLEAR DTCs and RETEST. |
T8 INTERMITTENT
- Key off.
- Restore vehicle.
- Clear DTCs.
- Turn key off, then turn key on.
- Perform KOEO On-Demand Self Test.
Did DTC 1663 reset?
| Yes | No |
|---|
| REPLACE the PCM. RESTORE vehicle. CLEAR DTCs and RETEST. | Unable to duplicate failure. System OK. RESTORE vehicle. CLEAR DTCs and RETEST. |
T: Introduction